Some 36 million European households are in high-rise residences, one in six of all households, and yet many of the buildings are in urgent need of refurbishment. This study, which is one in a series being conducted on behalf of the International Energy Agency addressing the energy performance of the existing IEA-wide building stock, identifies a Europe-wide cost-effective energy saving potential of 28% from energy-efficient refurbishment of the high-rise residential building stock. Attainment of this potential would imply a 1.5% reduction of Europe's total final energy demand and annual CO2 emissions savings of 35 Mt. In practice only the less efficient buildings need to be refurbished to realise these stockaverage savings and for these buildings typical savings in heating energy from refurbishment of between 70 and 80% are identified.
Buildings in general suffer from a variety of barriers that tend to prevent their occupants from maintaining and refurbishing them to levels of comfort and energy performance that would be justified over the longer term, but collective housing in general is particularly susceptible to market failures. Many occupants do not own the property while their landlords usually have little motivation to finance improvements. Refurbishment requires collective agreement on a capital investment, which is difficult to establish especially when some occupants expect to live in the building over the longer-term but others only for the short-term. Furthermore, in most cases the occupants of high-rise residences are not among the wealthier members of society and they find it difficult to raise capital for longer-term investments. It is not surprising, then, to find that this section of the building stock is the most neglected and that there remain significant cost-effective opportunities for it to be refurbished in a way that improves comfort, saves energy, reduces CO2 emissions and significantly improves the urban environment.